Method and system for determining uplink and downlink weights for antenna elements of modular antenna arrays

Abstract

Aspects of the subject disclosure may include, for example, receiving sounding reference signal (SRS) symbols from antenna elements of each of multiple modular antenna arrays, wherein the multiple modular antenna arrays are operatively combined to form a coherent antenna system, performing an uplink (UL) channel estimation and a downlink (DL) channel estimation, across a plurality of physical resource blocks (PRBs), based on the SRS symbols, calculating, for the antenna elements, a plurality of uplink (UL) combining weights based on the UL channel estimation and a plurality of downlink (DL) precoder weights based on the DL channel estimation, and causing the plurality of UL combining weights and the plurality of DL precoder weights to be applied to the antenna elements, thereby adjusting beamforming of the coherent antenna system. Other embodiments are disclosed.

What is claimed is: 
     
       1. A device, comprising:
 a processing system including a processor and positioned and configured at a centralized location as a virtual distributed unit (vDU) cluster; and 
 a memory that stores executable instructions that, when executed by the processing system, facilitate performance of operations, the operations comprising: 
 receiving sounding reference signal (SRS) symbols from antenna elements of each of multiple modular antenna arrays, wherein the multiple modular antenna arrays are operatively combined to form a coherent antenna system; 
 performing an uplink (UL) channel estimation and a downlink (DL) channel estimation, across a plurality of physical resource blocks (PRBs), based on the SRS symbols; 
 calculating, for the antenna elements, a plurality of uplink (UL) combining weights based on the UL channel estimation and a plurality of downlink (DL) precoder weights based on the DL channel estimation; and 
 causing the plurality of UL combining weights and the plurality of DL precoder weights to be applied to the antenna elements, thereby adjusting beamforming of the coherent antenna system. 
 
     
     
       2. The device of  claim 1 , wherein the calculating the plurality of UL combining weights and the plurality of DL precoder weights comprises performing matrix inversions across the coherent antenna system as a function of PRB, user equipment (UE), layer data, or a combination thereof. 
     
     
       3. The device of  claim 1 , wherein the performing the UL channel estimation and the DL channel estimation are based on one or more coherence block indicators. 
     
     
       4. The device of  claim 3 , wherein the one or more coherence block indicators are associated with one or more user equipment (UE). 
     
     
       5. The device of  claim 1 , wherein the plurality of PRBs is in the frequency domain. 
     
     
       6. The device of  claim 1 , wherein the performing the UL channel estimation comprises performing interpolation for one or more PRBs of the plurality of PRBs. 
     
     
       7. The device of  claim 1 , wherein the multiple modular antenna arrays are operable in multi-user (Mu)-multiple-input-multiple-output (MIMO) mode. 
     
     
       8. The device of  claim 1 , wherein the multiple modular antenna arrays are operable in single-user (Su)-MIMO mode. 
     
     
       9. The device of  claim 1 , wherein the multiple modular antenna arrays are operated in time division duplex (TDD), frequency division duplex (FDD), or a combination thereof. 
     
     
       10. The device of  claim 1 , wherein the antenna elements comprise all of the antenna elements of the multiple modular antenna arrays. 
     
     
       11. A method, comprising:
 obtaining, by a cluster of virtual distributed units (vDUs) including a plurality of processors, pilot signals from each antenna element of each modular antenna array of a combination of coherent modular antenna arrays; 
 estimating, by the cluster of vDUs and per physical resource block (PRB) of a plurality of PRBs, an uplink (UL) channel based on cross-correlation of the pilot signals with reference tones, and estimating a downlink (DL) channel; 
 determining, by the cluster of vDUs and based on the estimating the UL channel, a respective uplink (UL) weight for each antenna element of each modular antenna array of the combination of coherent modular antenna arrays, resulting in a set of UL weights; 
 calculating, by the cluster of vDUs and based on the estimating the DL channel, a respective downlink (DL) weight for each antenna element of each modular antenna array of the combination of coherent modular antenna arrays, resulting in a set of DL weights; and 
 applying, by the cluster of vDUs, the set of UL weights and the set of DL weights to the combination of coherent modular antenna arrays, thereby adjusting beamforming of the combination of coherent modular antenna arrays. 
 
     
     
       12. The method of  claim 11 , wherein the cluster of vDUs is located at a pooling site remote from the combination of coherent modular antenna arrays. 
     
     
       13. The method of  claim 11 , wherein the pilot signals comprise sounding reference signals (SRS). 
     
     
       14. The method of  claim 11 , wherein the obtaining, the estimating the UL channel, the estimating the DL channel, the determining, the calculating, and the applying are performed periodically. 
     
     
       15. The method of  claim 11 , wherein the determining involves matrix inversions, and wherein individual vDUs of the cluster of vDUs share or participate in determining of the matrix inversions. 
     
     
       16. A non-transitory machine-readable medium, comprising executable instructions that, when executed by a processing system operatively coupled to a combination of modular antenna panels and including a processor, facilitate performance of operations, the operations comprising:
 obtaining sounding reference signal (SRS) symbols from antenna elements of the combination of modular antenna panels; 
 performing an uplink (UL) channel estimation, across a plurality of physical resource blocks (PRBs), using the SRS symbols; 
 predicting a downlink (DL) channel, across the plurality of PRBs, using the SRS symbols, resulting in a predicted DL channel; 
 deriving, for the antenna elements, UL combining weights based on the UL channel estimation and DL precoder weights based on the predicted DL channel; and 
 causing the UL combining weights and the DL precoder weights to be applied to the antenna elements of the combination of modular antenna panels. 
 
     
     
       17. The non-transitory machine-readable medium of  claim 16 , wherein the combination of modular antenna panels is operated in multi-user (Mu)-multiple-input-multiple-output (MIMO) mode, single-user (Su)-MIMO mode, or a combination thereof. 
     
     
       18. The non-transitory machine-readable medium of  claim 16 , wherein the combination of modular antenna panels is operated in time division duplex (TDD), frequency division duplex (FDD), or a combination thereof. 
     
     
       19. The non-transitory machine-readable medium of  claim 16 , wherein the antenna elements comprise all of the antenna elements of the combination of modular antenna panels. 
     
     
       20. The non-transitory machine-readable medium of  claim 16 , wherein the performing the UL channel estimation and the predicting the DL channel are based on one or more coherence block indicators.